Joint structure for column material and column base fitting

ABSTRACT

At a joint between a butt end face of a lower end of the column material made of wood and a butt end receiving face of the column base fitting that supports the butt end face, an outer edge of the butt end face extends more outward than an outer edge of the butt end receiving face, and at a corner between the butt end face and a side face of the column material, a water draining function that causes water running along the side face of the column material to drop downward is provided.

TECHNICAL FIELD

The present invention relates to a joint structure for a column material made of wood and a column base fitting for fixing a lower end of the column material to a structure such as a foundation mainly in a wooden house.

BACKGROUND ART

In a building such as a wooden house, as in a conventional example shown in FIG. 4, there is known a mechanism such that a lower end of a column material (20) made of wood is joined to a foundation (15) via a column base fitting (1), to thereby transmit axial force of the column material (20) to the foundation (15) via the column base fitting (1).

On the other hand, the temperature under the floor of a building fluctuates relatively little due to influence of the ground, and thus if hot and humid outside air enters under the floor during the rainy season to early summer, dew condensation occurs on underfloor parts such as the foundation (15) and soil surface.

Then, if dew condensation occurs on an underfloor heat insulating material (41) installed on a lower face of a floor material (40) or side faces (26), (26) of the column material (20) under the floor, the dew condensation water runs along the side faces (26), (26) . . . of the column material (20) and flows down to the lower end of the column material (20), and then may enter a gap between the column material (20) and the column base fitting (1), thereby staying in the gap due to a capillary phenomenon. The accumulated water comes into contact with a butt end face (24) of the column material (20) having high water absorption capacity, and water absorption from the butt end face (24) increases the water content of the column material (20) and makes the environment favorable for growth and activity of rotting fungi. Thus, there is a problem that the column material (20) becomes perishable.

On the other hand, Patent Literature 1 below describes a structure such that a plate-shaped water blocking member for preventing absorption of dew condensation water on the butt end face is interposed between the butt end face of the lower end of the column material and the column base fitting, and thus decay of the column material can be suppressed.

CITATION LIST Patent Literature

Patent Literature 1: JP 2003-213803 A

SUMMARY OF THE INVENTION Technical Problems

However, the water blocking member described in Patent Literature 1 is for preventing the dew condensation water generated on the column base fitting side from infiltrating the column material side. Although it is thus possible to effectively stop the dew condensation water generated below the butt end face of the column material by using such a water blocking member, dew condensation water generated above the butt end face runs along the side face of the column material and flows down to the lower end of the column material, and thereafter may enter between the butt end face and the water blocking member, and thus it has not been possible to sufficiently prevent water absorption from the butt end face.

Accordingly, it is an object of the present invention to provide a joint structure of a column material and a column base fitting which can improve durability of the column material by eliminating the above-mentioned problems and preventing the dew condensation water running down the side face of the column material made of wood from being absorbed by the column material from the butt end face.

Solutions to the Problems

To solve the above-described problems, a joint structure for the column material and the column base fitting according to the present invention is characterized in that at a joint between a butt end face of a lower end of the column material made of wood and a butt end receiving face of the column base fitting that supports the butt end face, an outer edge of the butt end face extends more outward than an outer edge of the butt end receiving face, the joint structure comprising, at a corner between the butt end face and a side face of the column material, a water draining function that causes water running along the side face of the column material to drop downward.

In addition, an outer edge of a water blocking layer interposed between the butt end face and the butt end receiving face is located more inside than the outer edge of the butt end face so as not to interfere with the water draining function.

Further, the outer edge of the water blocking layer extends more outward than the outer edge of the butt end receiving face.

Furthermore, a water repellent agent is applied to a lower end portion of the side face of the column material. Further, the water repellent agent is applied to the butt end face.

Advantageous Effects of Invention

In a joint structure for a column material and a column base fitting according to the present invention, at a joint between a butt end face of a lower end of the column material and a butt end receiving face of the column base fitting, an outer edge of the butt end face extends more outward than an outer edge of the butt end receiving face, and a corner between the butt end face and a side face of the column material has a water draining function that causes water running along the side face of the column material to drop downward. That is, even if dew condensation water generated on an underfloor heat insulating material, the side face of the column material, or the like runs along the side face of the column material and flows down to the lower end of the column material, the dew condensation water can be prevented from adhering to and staying on the outer edge of the butt end receiving face or from entering the gap between the butt end face and the butt end receiving face. Therefore, it is possible to prevent infiltration of dew condensation water on the butt end face having a high water absorption capacity, and thereby it is possible to suppress an increase in water content of the column material and to improve durability of the column material.

Further, an outer edge of a water blocking layer interposed between the butt end face and the butt end receiving face is located more inside than the outer edge of the butt end face so as not to interfere with the water draining function described above, and thus it is possible to prevent the dew condensation water that has flowed down to the lower end of the side face of the column material from adhering to the outer edge of the water blocking layer. That is, by providing the water blocking layer, while the dew condensation water generated on the column base fitting side is stopped, the dew condensation water running along the side face of the column material can be prevented from staying in a state of adhering to the outer edge of the water blocking layer, or from entering the gap between the butt end face and the water blocking layer, and water absorption on the butt end face can be reliably prevented.

Furthermore, by the outer edge of the water blocking layer extending more outward than the outer edge of the butt end receiving face, movement of the dew condensation water between the butt end face and the butt end receiving face is completely blocked, and the dew condensation water generated on the column base fitting side can be reliably stopped. Moreover, even if the dew condensation water running down along the side face of the column material adheres to the outer edge of the water blocking layer by any chance, the dew condensation water can be dropped downward without adhering to the butt end receiving face.

Furthermore, by applying a water repellent agent to a lower end portion of the side face of the column material, the dew condensation water that has run and flowed down along the side face of the column material can smoothly drop downward, retention of water near the butt end face is effectively prevented, and the above-mentioned water draining function can be further improved. Further, by applying the water repellent agent to the butt end face, even if the dew condensation water running along the side face of the column material sneaks around to the butt end face by any chance, the dew condensation water is repelled by the water repellent agent that covers the butt end face, and thus absorption of the dew condensation water from the butt end face can be prevented more reliably.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a joint structure for a column material and a column base fitting in one embodiment according to the present invention.

FIG. 2 is a perspective view showing a joint structure for a column material and a column base fitting in one embodiment according to the present invention.

FIG. 3 is an exploded perspective view showing a joint structure for a column material and a column base fitting in one embodiment according to the present invention.

FIG. 4 is a sectional view showing the conventional joint structure for a column material and a column base fitting.

DESCRIPTION OF EMBODIMENT

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In FIGS. 1 to 3, (1) denotes a column base fitting used for joining a lower end of a column material (20) made of wood to a foundation (15).

The column base fitting (1) includes a base plate (2) placed on an upper face of the foundation (15), a support plate (3) that supports the lower end of the column material (20) above the base plate (2), and an insertion plate (4) provided to stand on an upper face of the support plate (3).

The base plate (2) and the support plate (3) has, for example, a rectangular shape, and are provided at an interval above and below so as to be parallel to each other. The base plate (2) and the support plate (3) are connected by, for example, welding with a spacer (5) having a substantially cross-shaped cross section extending along a column axis direction of the column material (20).

In the base plate (2), bolt insertion holes (6), (6) . . . are formed respectively at four positions separated by the spacer (5). Then, upper end portions, which are exposed above the foundation (15), of anchor bolts (9), (9) implanted in the foundation (15) are inserted through, for example, two diagonal bolt insertion holes (6), (6) out of the four bolt insertion holes (6), (6) . . . of the base plate (2), and nuts (10), (10) are screwed and fastened onto the upper end portions of the anchor bolts (9), (9) from above, thereby fixing the column base fitting (1) on the foundation (15). Note that the support plate (3) is provided with work holes (7) at appropriate positions, so that the nuts (10), (10) can be easily fastened.

The upper face of the support plate (3) is a butt end receiving face (12) on which the butt end face (24) at the lower end of the column material (20) is placed. The butt end receiving face (12) has a square shape with a side length of, for example, 105 mm, but the shape and dimensions thereof are not particularly limited.

As shown in FIG. 1, the insertion plate (4) is provided so as to rise from the butt end receiving face (12) of the support plate (3) along the column axis direction, and is connected by welding to the support plate (3), for example. Further, as shown in FIG. 3, the insertion plate (4) is formed in a substantially rectangular shape, and both side corners at an upper end thereof have a rounded shape. Further, at the upper end portions of the insertion plate (4), for example, a pair of pin insertion holes (8), (8) are arranged side by side along the horizontal direction.

On the other hand, a slit (21) for inserting the insertion plate (4) of the column base fitting (1) is formed in the lower end of the column material (20). The slit (21) is provided along the column axis direction and penetrating across the side faces (26), (26) of the column material (20) facing each other. Further, at a lower end portion of the column material (20), for example, a pair of pin insertion holes (22), (22) are formed so as to correspond to the pin insertion holes (22), (22) of the insertion plate (4). These pin insertion holes (22), (22) are provided penetrating along a direction substantially orthogonal to the slit (21) and between the side faces (26), (26) of the column material (20) facing each other.

The butt end face (24) at the lower end of the column material (20) is larger than the butt end receiving face (12) of the column base fitting (1), and has a square shape with a side length of, for example, 120 mm. Thus, as shown in FIGS. 1 and 2, in a state where the butt end face (24) is placed on the butt end receiving face (12) of the column base fitting (1), an outer edge of the butt end face (24) extends more outward than an outer edge of the butt end receiving face (12). At this time, an extension width of the outer edge of the butt end face (24) with respect to the outer edge of the butt end receiving face (12) is 7.5 mm, but the extension width is not necessarily limited to this and is only required to be a width such that the dew condensation water running down the side face of the column material (20) and reaching the lower end does not come into contact with the outer edge of the butt end receiving face (24).

A water repellent agent (29) is applied to lower end portions of the side faces (26), (26) . . . of the column material (20) over the entire circumference, and thereby the dew condensation water running down the side faces (26), (26) . . . of the column material (20) is repelled by the water repellent agent (29) and falls smoothly downward. Further, the water repellent agent (29) is applied also to the entire face of the butt end face (24) at the lower end of the column material (20), and dew condensation water that has sneaked around by any chance from the side faces (26), (26) . . . of the column material (20) to the butt end face (24) is repelled by the water repellent agent (29) and thus can be prevented from being absorbed from the butt end face (24) into the column material (20). Note that as the water repellent agent (29), a silicon-based or fluorine-based or other synthetic resin is used, but the water repellent agent (29) is not particularly limited.

Further, a water blocking layer that blocks movement of water between the butt end face (24) and the butt end receiving face (12) is interposed between the butt end face (24) of the column material (20) and the butt end receiving face (12) of the column base fitting (1), and for example, a pair of water blocking sheets (16), (16) are used as the water blocking layer.

Each of the water blocking sheet (16) has, for example, a rectangular shape and a width in a short side direction that is approximately half the width in a long side direction, as shown in FIG. 3. Further, the width of the water blocking sheet (16) in the long side direction is formed so as to be larger than the width of the butt end receiving face (12) and smaller than the width of the butt end face (24).

Then, in a state where the long side directions of the water blocking sheets (16), (16) are parallel to a surface direction of the insertion plate (4) of the column base fitting (1), one of the water blocking sheets (16) is attached to one side of the insertion plate (4), and the other water blocking sheet (16) is attached to the other side of the insertion plate (4). Thus, the water blocking sheets (16), (16) can be attached between the butt end face (24) and the butt end receiving face (12) without interfering with the insertion plate (4).

Note that it is not always necessary to use two water blocking sheets (16), (16) as the water blocking layer, and only one square water blocking sheet may be used. In that case, it is conceivable to avoid interference with the insertion plate (4) by forming a linear notch in the substantially central portion of the water blocking sheet.

As the water blocking sheets (16), (16), those having a water stopping property are used, and for example, a foamed (independently foamed) polyethylene resin is preferably used. However, the materials of the water blocking sheets (16), (16) are not particularly limited, and may be, for example, rubber, vinyl-based, or other synthetic resin.

When joining the column material (20) to the column base fitting (1) fixed to the foundation (15), first, as shown in FIG. 3, the water blocking sheets (16), (16) are placed on both sides of the insertion plate (4) in the butt end receiving face (12) of the column base fitting (1). In this state, outer edges of the water blocking sheets (16), (16) extend more outward than the outer edge of the butt end receiving face (12) as shown in FIGS. 1 and 2.

Subsequently, as shown in FIG. 3, while inserting the insertion plate (4) of the column base fitting (1) into the slit (21) of the column material (20), the butt end face (24) of the lower end of the column material (20) is placed on the butt end receiving face (12) of the column base fitting (1) with the water blocking sheets (16), (16) interposed therebetween. Thus, the water blocking sheets (16), (16) are sandwiched and held between the butt end face (24) and the butt end receiving face (12). Further, in this state, as shown in FIGS. 1 and 2, the outer edge of the butt end face (24) at the lower end of the column material (20) is in a state of extending more outward than the outer edge of the butt end receiving face (12) of the column base fitting (1) and the outer edges of the water blocking sheets (16), (16).

Thereafter, drift pins (23), (23) are inserted through the pin insertion holes (22), (22) of the column material (20) and the pin insertion holes (8), (8) of the insertion plate (4) inserted into the slit (21) of the column material (20), thereby joining the column material (20) to the column base fitting (1).

Note that as shown in FIG. 2, an opening of the slit (21) in the side faces (26), (26) of the column material (20) can be closed with a caulking agent (30) made of a silicon-based resin, for example, so as to reliably prevent dew condensation on the insertion plate (4) in the slit (21), but this caulking treatment is not always necessary.

In a state where the column material (20) and the column base fitting (1) are joined in this manner, at a joint between the butt end face (24) and the butt end receiving face (12), as shown in FIGS. 1 and 2, the dew condensation water does not adhere to the butt end receiving face (12) when the dew condensation water running down the side faces (26), (26) . . . of the column material (20) reaches the lower end of the column material (20) because the outer edge of the butt end face (24) extends more outward than the outer edge of the butt end receiving face (12).

That is, by the outer edge of the butt end face (24) extending more outward than the outer edge of the butt end receiving face (12), a water draining function that causes water running along the side faces (26), (26) . . . of the column material (20) to drop downward is provided at corners (25), (25) . . . between the butt end face (24) and the side faces (26), (26) . . . of the column material (20), and thus the dew condensation water that has reached the corners (25), (25) . . . does not stay in a state of adhering to the outer edges of the water blocking sheets (16), (16) or does not enter the gap between the butt end face (24) and the water blocking sheets (16), (16), and drops smoothly downward.

At this time, because the water repellent agent (29) is applied to the lower end portions of the side faces (26), (26) . . . of the column material (20), the dew condensation water can be reliably prevented from staying near the butt end face (24), and the water draining function of the corner (25) of the column material (20) is enhanced. Further, because the water repellent agent (29) is also applied to the butt end face (24), even if the dew condensation water running along the side faces (26), (26) . . . of the column material (20) sneaks around to the butt end face (24) by any chance, the dew condensation water is repelled by the water repellent agent (29), and thus water absorption at the butt end face (24) can be reliably prevented.

Further, because the water blocking sheets (16), (16) are interposed between the butt end face (24) and the butt end receiving face (12), and the water blocking sheets (16), (16) block movement of the dew condensation water generated on the column base fitting (1) side to the column material (20) side, it is possible to address not only dew condensation generated on the upper side of the butt end face (24) but also dew condensation generated on the lower side of the butt end face (24).

Moreover, the outer edges of the water blocking sheets (16), (16) are located more inside than the outer edge of the butt end face (24) so as not to interfere with the water draining function of the corner (25) of the column material (20), and thus the dew condensation water that has flowed down to the lower end of the side faces (26), (26) . . . of the column material (20) does not adhere to and stay on the outer edges of the water blocking sheets (16), (16) or does not enter the gap between the butt end face (24) and the water blocking sheets (16), (16), and reliably drops downward from the corners (25), (25) . . . of the lower end of the column material (20).

Furthermore, since the outer edges of the water blocking sheets (16), (16) extend more outward than the outer edge of the butt end receiving face (12), movement of the dew condensation water is completely blocked between the butt end face (24) and the butt end receiving face (12), the dew condensation water generated in the column base fitting (1) can be reliably stopped, and even if the dew condensation water running down the side faces (26), (26) . . . of the column material (20) adheres to the outer edges of the water blocking sheets (16), (16) by any chance, the dew condensation water drops downward without adhering to and staying on the butt end receiving face (12).

Note that the present invention is not limited to the above embodiment, and as a matter of course, many modifications and changes can be made to the above embodiment within the scope of the present invention. For example, the water blocking sheets (16), (16) are used as the water blocking layer in the above, but a water blocking layer may be formed instead of the water blocking sheets (16), (16) by using a hard plate or by filling and curing a liquid watertight agent.

DESCRIPTION OF REFERENCE SIGNS

-   1 column base fitting -   12 butt end receiving face -   16 water blocking sheets -   20 column material -   24 butt end face -   25 corner -   26 side face of the column material -   29 water repellent agent 

1. A joint structure for a column material and a column base fitting in which at a joint between a butt end face of a lower end of the column material made of wood and a butt end receiving face of the column base fitting that supports the butt end face, an outer edge of the butt end face extends more outward than an outer edge of the butt end receiving face, the joint structure comprising, at a corner between the butt end face and a side face of the column material, a water draining function that causes water running along the side face of the column material to drop downward.
 2. The joint structure for the column material and the column base fitting according to claim 1, wherein an outer edge of a water blocking layer interposed between the butt end face and the butt end receiving face is located more inside than the outer edge of the butt end face so as not to interfere with the water draining function.
 3. The joint structure for the column material and the column base fitting according to claim 2, wherein the outer edge of the water blocking layer extends more outward than the outer edge of the butt end receiving face.
 4. The joint structure for the column material and the column base fitting according to claim 3, wherein a water repellent agent is applied to a lower end portion of the side face of the column material.
 5. The joint structure for the column material and the column base fitting according to claim 4, wherein the water repellent agent is applied to the butt end face. 